With a rapid development of vehicle electronics technology, functionalities of vehicles are becoming more and more complicated, and vehicle diagnosis is becoming more and more important, vehicle diagnostic equipments play a very important role in people's daily lives. As for the diagnostic equipment, lower computer programs of the diagnostic equipment are core programs that serve to communicate with an ECU (Electronic Control Unit) of vehicle. Due to development of vehicles, the lower computer programs of the diagnostic equipment need to be updated to be supportive of diagnosis of new types of vehicles, diagnostic software and the lower computer programs work as a whole by combination and coexistence.
However, a lawbreaker may operate an upper computer reversely so as to use data of a certain type of vehicle to cheat the lower computer of the diagnostic equipment, thereby evading a validity check of the lower computer programs, and achieving a purpose of illegally communicating with the ECU of the vehicle.